The present invention relates to method and apparatus for accumulating and feeding a ribbon material. More particularly the present invention concerns sensing to maintain a desired paper fold level in feed chute by speed of a take-away conveyor, reversing the lean of a stored zig-zag folded pile of ribbon material such that the ribbon is removed from the top of the pile rather than the bottom, sensing the level of the folded pile in the storage area to control the volume of ribbon supplied to the end use and a specific feed wheel arrangement for acting to stiffen the ribbon to promote zig-zag folding in a desired manner.
It is known in the art to accumulate ribbon material by folding it in a zig-zag pile and delivering it from the pile via a conveyor to an end use. It is, however, an object of the herein apparatus to supply sufficient ribbon material that an end use may be operated continuously while a roll of ribbon material to be unwound is replaced. Hence it is desirable to store up to 5,000 lineal feet of ribbon in a storage area. When dealing with this much ribbon the weight of the ribbon becomes a factor and removing ribbon from the bottom of the pile with the weight of the entire pile placed thereon creates a potential for the ribbon to break.
Means are provided for reversing the lean of the pile as it is transported away from the stacking area such that the pile is inclined backwardly and additional ribbon being removed therefrom is removed from the bottom of the pile. Hence the weight of the pile is no longer on the portion of the ribbon being removed and the integrity of the ribbon through the process is greatly increased.
An array of optical level detectors includes a plurality of rows of level detectors spaced through the stacking area to sense the height of ribbon pile present. By sensing the top layer of the pile, the take-away conveyor speed to maintain the pile at the desired level may be varied. If the pile becomes too high, the conveyor speed is increased whereas if the pile height is insufficient the conveyor speed is decreased while the feeder roller rate remains constant.
Additionally the herein invention includes the utilization of tire-like members located on the feed wheels. These tire members have a width less than the width of the ribbon passing therebetween. By acting on only a portion of the ribbon the tires act to slightly deform the ribbon thereby stiffening the material. By stiffening the material, the manner in which the ribbon is folded in the zig-zag pile is regulated. When the ribbon is stiffer it tends to fold in a zig-zag pile having large loops as desired.